The present invention relates to an image forming device for processing image data, which is provided with multiple functions such as of a printer, a copier, a facsimile, a scanner and so on. More specifically, the invention relates to an image forming device capable of temporarily suspending a current job on receipt of an interrupt request and performing the requested job following the interrupt, ensuring that the job suspended by the interrupt may be successfully resumed and completed by printing all image data on paper without causing an error signal “no paper” for the job.
In the art, there are known image forming devices capable of temporarily suspending a current job by an interrupt request and performing the requested job following the interrupt, which devices are for example as follows:
Japanese Laid-Open Patent Publication No. 8-18719 discloses a printer device with a facsimile transmitter, the device is capable of receiving facsimile information and also printing data outputted from a personal computer and which has a mode settable to prohibit an interrupt from a facsimile transmission in case of printing urgent and important online data from a personal computer.
Japanese Laid-Open Patent Publication No. 11-168590 discloses a digital copying machine capable of printing data inputted from its scanner portion as well as data inputted from any external unit connected thereto. The machine can check the necessity of interrupting a current job to perform another job on the basis of its emergency, so that a current emergent printing job or printing only one page may not be put off against a user's will.
In the above examples, it is not ensured that a temporarily interrupted or suspended job can be successfully finished after the end of the interruption. Namely, such suspended or interrupted job may be suspended again for example with an error signal “no paper” as a result of consumption of paper by the interrupting job. In the other words, some users may accept, an interrupt request for another printing job to postpone the current printing job on condition that the current printing job is resumed later and completed without the occurrence of an error signal “no paper” due to the consumption of the paper by the interrupting job.